<HoverContainer>

The [base case](hover:one) returns 1.

```cpp
int factorial(int n) {
  if (n == 0) {
    // !hover one
    return 1;
  } else {
    // !hover two
    return n * factorial(n - 1);
  }
}
```

The [recursive case](hover:two) multiplies something.

</HoverContainer>
